Vicks thermometer screen: Err, Lo, Hi, F1, F2, F3, CLR and the colours
Two Vicks owner’s manuals are quoted here: the VNT275CA non-contact forehead thermometer and the SpeedRead V912CA stick thermometer. Each state below says which model it belongs to, with Vicks’ own words in quotation marks and what Vicks says to do.
Check your thermometer’s manual — makers differ.
All 16 Vicks screen states at a glance
| On the screen | What Vicks’s manual says it means |
|---|---|
Err | A malfunction (SpeedRead V912CA stick) |
Lo at switch-on | The ready screen, not a reading (SpeedRead V912CA stick) |
Flashing °C or °F | Measuring; it stops flashing when done (SpeedRead V912CA stick) |
Lo or Hi after measuring | Outside the range it reports (SpeedRead V912CA stick) |
Green, yellow or red screen | Vicks’ Fever InSight colour (SpeedRead V912CA stick) |
Flashing battery symbol | Battery exhausted (SpeedRead V912CA stick) |
All segments lit for 2 seconds | Self-test at the start of a measurement (VNT275CA forehead) |
Green, yellow or red backlight | Vicks’ Fever InSight colour (VNT275CA forehead) |
Body or Surface | Which mode it is measuring in (VNT275CA forehead) |
F1 | The °C / °F setting (VNT275CA forehead) |
F2 | The fever-alert setting (when the screen turns red) (VNT275CA forehead) |
F3 | The sound setting (VNT275CA forehead) |
----°C or ----°F | An empty memory slot (VNT275CA forehead) |
CLR | The memory has been cleared (VNT275CA forehead) |
rst | Factory reset (VNT275CA forehead) |
Flashing or steady battery symbol | Batteries low, or too low to measure (VNT275CA forehead) |
Which models this covers
Vicks thermometers are made by Kaz, a Helen of Troy company, which also makes Braun thermometers. Both manuals are Vicks Canada’s, from the product pages on vickshumidifiers.ca; the US site (vickshumidifiers.com) answered our request with HTTP 403 on 2026-10-13. Neither manual lists numbered errors such as Err 1, Err 2 or Err 3, so this page does not explain them.
Each state, in Vicks’s words
Err A malfunction
Vicks SpeedRead V912CA stick
“The display will read “Err” when a malfunction occurs and the unit will power off after 1 minute.”
The V912CA manual gives no number after Err and no fix beyond the thermometer switching itself off; for help it gives the Vicks Consumer Relations line, 1-800-477-0457.
Every make: Err or Er with a number. Source: Vicks SpeedRead Digital Thermometer V912CA — owner’s manual (Canada, English and French, PDF) Checked 2026-10-13.
Lo at switch-on The ready screen, not a reading
Vicks SpeedRead V912CA stick
“After about 5 seconds, the display will show it’s ready (Fig. 4).”
“With power off, press and hold the power button for about 5 seconds until “Lo” (Fig. 4) appears in the screen.”
Both sentences point to the same Fig. 4, the “Lo” screen: on this stick thermometer, Lo before you start means it is ready, because the probe is still colder than the range it reports.
Every make: Lo on a thermometer. Source: Vicks SpeedRead Digital Thermometer V912CA — owner’s manual (Canada, English and French, PDF) Checked 2026-10-13.
Flashing °C or °F Measuring; it stops flashing when done
Vicks SpeedRead V912CA stick
“After about 3 seconds the unit is ready to take a reading (°C or °F symbol starts flashing).”
“When the peak temperature is reached (usually 9 seconds), 5 beep signals will sound and the “°C” sign will stop flashing.”
Vicks gives about 9 seconds by mouth, 11 under the arm and 10 rectally before the flashing stops.
Every make: Flashing °C, °F or mode symbol. Source: Vicks SpeedRead Digital Thermometer V912CA — owner’s manual (Canada, English and French, PDF) Checked 2026-10-13.
Lo or Hi after measuring Outside the range it reports
Vicks SpeedRead V912CA stick
“Temperature Range: 32.0°C~43°C (89.6°F-109.4°F). If less than 32°C (89.6°F), “Lo” is displayed.”
“If more than 43°C (109.4°F), “Hi” is displayed.”
Lo after a measurement is different from Lo at switch-on: it means the reading came out below the range Vicks prints.
Every make: Hi on a thermometer. Source: Vicks SpeedRead Digital Thermometer V912CA — owner’s manual (Canada, English and French, PDF) Checked 2026-10-13.
Green, yellow or red screen Vicks’ Fever InSight colour
Vicks SpeedRead V912CA stick
“The screen displays Green for a Normal temperature, Yellow for a Fever and a Red for a High Fever. Five (5) rapid audible beeps indicate temperatures over 38.5°C (101.3°F) alerting that the individual may have a fever.”
Vicks also says the display flashes red, yellow and green for 1 second each time you switch it on; that start-up flash is not a result.
Every make: Fever colours and fever symbol. Source: Vicks SpeedRead Digital Thermometer V912CA — owner’s manual (Canada, English and French, PDF) Checked 2026-10-13.
Flashing battery symbol Battery exhausted
Vicks SpeedRead V912CA stick
“appears and flashes in the center top of the display, the battery is exhausted and needs replacing.”
What Vicks says to do: “Replace the battery with a CR1632 silver oxide type or equivalent.”
Vicks’ sentence begins with the battery symbol itself, drawn in the manual. On this stick thermometer a flashing battery means replace it now, not soon.
Every make: Low battery symbol. Source: Vicks SpeedRead Digital Thermometer V912CA — owner’s manual (Canada, English and French, PDF) Checked 2026-10-13.
All segments lit for 2 seconds Self-test at the start of a measurement
Vicks VNT275CA forehead
“Align the device to forehead at a distance of 1-5cm (0.4-2.0 inches), then press the On (Trigger) button to start the measurement and read the data. The thermometer will perform a self-test with all segments displayed for 2 seconds.”
Every symbol lighting up together is the self-test, not a set of warnings.
Source: Vicks Non Contact Infrared Body Thermometer VNT275CA — owner’s manual (Canada, PDF) Checked 2026-10-13.
Green, yellow or red backlight Vicks’ Fever InSight colour
Vicks VNT275CA forehead
“Green means the body temperature is normal. If 37.4°C – 38.4°C (99.3°F – 101.1°F), yellow is displayed, which means slight fever warning.”
“When the body temperature is above 38.4°C(101.1°F), red is displayed, which means high fever.”
“1. Surface mode always displays temperature with a Green backlight. 2. In body mode, 34.0- 35.6°C (93.2-96.1°F) will be displayed with a No LED backlight.”
A green backlight in surface mode says nothing about fever. The red point can also be moved in the F2 setting, so a changed F2 changes the colours.
Every make: Fever colours and fever symbol. Source: Vicks Non Contact Infrared Body Thermometer VNT275CA — owner’s manual (Canada, PDF) Checked 2026-10-13.
Body or Surface Which mode it is measuring in
Vicks VNT275CA forehead
“When the device is on, pressing the MODE button to cycle conversion between “body” mode and “surface” mode.”
““body” mode is used for measuring human body temperature, the “surface “ mode is used to measure the surface temperature. (The factory default is “body” mode).”
A reading taken with Surface showing is the temperature of the skin or object, not a body temperature.
Every make: Body, forehead, object or room mode symbol. Source: Vicks Non Contact Infrared Body Thermometer VNT275CA — owner’s manual (Canada, PDF) Checked 2026-10-13.
F1 The °C / °F setting
Vicks VNT275CA forehead
“Turn the thermometer on, press and hold the SET button to enter F1, press the “MODE” or “MEMO” button to switch Celsius and Fahrenheit temperature units, press the trigger to confirm the unit settings (factory default is Celsius).”
F1 is a settings screen, not an error code.
Every make: °C or °F on the display. Source: Vicks Non Contact Infrared Body Thermometer VNT275CA — owner’s manual (Canada, PDF) Checked 2026-10-13.
F2 The fever-alert setting (when the screen turns red)
Vicks VNT275CA forehead
“This setting will change at what point the backlight colour of the temperature reading turns to red.”
“The factory default and highly recommended temperature to have this set at is 38.5°C (101.3°F).”
Vicks puts F2 under advanced settings and warns: “The following settings are only meant to be used by professionals.”
Source: Vicks Non Contact Infrared Body Thermometer VNT275CA — owner’s manual (Canada, PDF) Checked 2026-10-13.
F3 The sound setting
Vicks VNT275CA forehead
“This setting will change the buzzer to be on or off.”
What Vicks says to do: “Press the “MODE” or the “MEMO” button to turn the volume on or off. Press the “SET” button to save this setting.”
F3 follows F2 when you press SET again.
Source: Vicks Non Contact Infrared Body Thermometer VNT275CA — owner’s manual (Canada, PDF) Checked 2026-10-13.
----°C or ----°F An empty memory slot
Vicks VNT275CA forehead
“An empty memory cell shows “----°C” or “----°F”.”
The VNT275CA keeps up to 50 readings; dashes in memory mean that slot has no reading yet.
Every make: M, memory number or memory icon. Source: Vicks Non Contact Infrared Body Thermometer VNT275CA — owner’s manual (Canada, PDF) Checked 2026-10-13.
CLR The memory has been cleared
Vicks VNT275CA forehead
“While the thermometer is on, press the MEMO button until the LCD display “CLR”, which means that all stored data is cleared completely.”
After CLR the stored readings are gone.
Every make: M, memory number or memory icon. Source: Vicks Non Contact Infrared Body Thermometer VNT275CA — owner’s manual (Canada, PDF) Checked 2026-10-13.
rst Factory reset
Vicks VNT275CA forehead
“press and hold the “MODE” button until the LCD displays “rst”. After 2 seconds the factory settings will be restored to the device.”
Vicks gives this as the way back to the factory settings at any point.
Source: Vicks Non Contact Infrared Body Thermometer VNT275CA — owner’s manual (Canada, PDF) Checked 2026-10-13.
Flashing or steady battery symbol Batteries low, or too low to measure
Vicks VNT275CA forehead
“Low Battery Warning: When the battery is running low, the display flashes the low battery warning symbol; however, the device can still work until the battery life has 0% left”
“Battery capacity is too low. Taking temperature is not allowed.”
What Vicks says to do: “Install a new battery. See “Replacing the Battery” for instructions.”
The VNT275CA takes 2 AAA batteries, according to its manual.
Every make: Low battery symbol. Source: Vicks Non Contact Infrared Body Thermometer VNT275CA — owner’s manual (Canada, PDF) Checked 2026-10-13.
These pages report what each maker’s manual says and quote it wherever health is involved. They do not diagnose anything, they are not medical advice, and they do not tell you whether a temperature is a fever or what to do about it; only your own thermometer’s manual and your doctor or nurse can do that for the person you are looking after.
Other thermometer makers
Sources
Every state above is quoted from these documents on Vicks’s own website, fetched and read on the date shown. Words in quotation marks are Vicks’s; everything else is ours.
- Vicks: Vicks Non Contact Infrared Body Thermometer VNT275CA — owner’s manual (Canada, PDF) Checked 2026-10-13.
- Vicks: Vicks SpeedRead Digital Thermometer V912CA — owner’s manual (Canada, English and French, PDF) Checked 2026-10-13.